Resistive memory devices are non-volatile memory devices employing non-volatile and reversible changes in resistance in a thin film with application of electrical voltage bias. As a “non-volatile” memory device, data stored in the resistive memory element does not change the value even when the power is turned off. In other words, the stored value of the data in any functional resistive memory device remains the same until the resistive memory element is reprogrammed, for example, in an erase operation or in a programming operation. The data stored in the non-volatile memory device can be reversed only when an electrical bias is applied in a direction that changes the resistive state of the memory device.
The resistive memory element is typically provided as a thin film, which is a solid-state material. Data can be stored in a resistive memory element by changing the resistance of the thin film. The thin film is referred to as a memory film or a read/write film. Examples of resistive random access memory (ReRAM) devices are described in World Intellectual Property Organization (WIPO) Publication No. WO2007004843 A1 to Hong et al. and U.S. Patent Application Publication No. 2013/0043455 A1 to Bateman.